The invention relates to a coupler arrangement.
The known coupler arrangements comprise a coupler arm, which is partially disposed in an underframe of a railway car, the said coupler arm being connected with the draw gear of a shock absorber by means of a coupler pin, whereas on the walls of the chamber there are provided front and rear stop means. The space contained between the front and rear stop means, the bottom of the draw gear and the head of the coupler arm is used to locate the cushioning device therein. The said space is usually rectangular in section. In the known embodiments the cushioning device comprises usually a friction-spring damper, a liquid spring or a rubber damper.
A known shock absorber fastening means for an autocoupler is disclosed in the Polish patent application No. 280535 which describes a shock absorber which is provided with a collar mounted between the ends of a casing, with said collar adhering, at the extreme distance from the end sill to the vertical supporting elements of the side walls of the chamber, with the said vertical elements resting on horizontal ribs at the side opposite to the end sill.
The disadvantage of the above coupler arrangements relies in operating restrictions caused by employed shock absorbers. Difficulties have been encountered when assembling hitherto known cushioning devices in a pocket of an automatic coupler, which was due to the fact that the cushioning device needed to be compressed in a press and transferred in this form to the coupler pocket by means of a special appliance.
Polish utility design application W-97130 describes a cushioning device whose casing has a shape of a sleeve closed with a bottom on one side, with the cylindrical elastomeric shock absorber being located in the said casing, with the piston rod of the said elastomeric shock absorber pointing towards the bottom of the sleeve and pressed upon the said bottom by means of a stop plate. The said stop plate is connected to the casing by means of screws which are fixedly attached to a stop plate, while in the casing the said screws pass through the bores in the lugs, which are located at the end of the casing opposite the bottom. Under the bolt heads there are provided U-shaped assembling washers.
Morover the description of the embodiments of the mentioned utility design application discloses that the cushioning device is mounted between the stop means. The front stop means that a stop plate abuts and the rear stop means which supports the bottom of the casing.
The disadvantage of the above device relies in the high cost of manufacturing the casing.
It is one important object of the present invention to obviate the above identified problems and disadvantages associated with known coupler arrangements.
In the accomplishment of this object, the cushioning device comprises an elastomeric shock absorber, whose bottom portion is mounted on a rear stop plate supported on the rear stop means, while the opposite portion of the shock absorber is slidably mounted in a casing. The said casing includes a guide bar, which is closed by a front stop plate. Inside the casing the piston rod of the elastomeric shock absorber abuts the said stop plate and this in turn abuts the front stop means. Location of the elastomeric shock absorber in the guide bar of a casing enhances the durability of the cushioning device because it protects the piston rod and the sealing means from the impact of transverse or side forces. Morover mounting the bottom portion of the elastomeric shock absorber on a rear stop block enables one to use and/or employ a longer shock absorber in the coupler pocket of the same size.
According to the present invention it is advantageous to employ a contractible mounting of the bottom section of the elastomeric shock absorber in a bore provided in a rear stop plate.
It is also advantageous to employ a guide bar whose length is smaller than the distance between the front stop plate and the rear stop plate of a fully compressed cushioning device. Due to this the excess force imposed on the cushioning device is transmitted by the cylinder of the elastomeric shock absorber after the pitch of the piston rod has been exhausted.
The guide bar has a shape of a sleeve in which a cylinder of elastomeric shock absorber is located and morover the said sleeve may be equipped with lugs, in which screw bolts are slidably installed, the said screw bolts being fixedly attached to the rear stop plate.
The guide bar may also have a shape like that of a box and in this case the cylinder of the elastomeric shock absorber on the side opposite to the bottom is provided with a flange.
Further improvements according to the invention are achieved by employing a box-shaped guide bar, which as a rectangular cross-section. In this case, in order to simplify the assembling procedure, it is preferred if the bottom section of the guide is shorter than the distance between the front stop block and the surface of the flange facing the rear stop block. In the case of the rectangular guide the flange is shaped as a rectangular plate preferably fixedly attached to a cylinder of the elastomeric shock absorber.